Those strange denominations are silly to me. Maybe a sign of silver hitting a peak frenzy of popularity from 2011 to 2013. Reminds me how there are a bunch of weird art bars minted around 1979 and 1980... a previous silver frenzy.

By the way, at least Zinc isn't as worthless as Iron. Zinc is rarer, and has additional properties, like helping the body destroy viruses :)